[sil (Steve)]

I haven't seen that iss tracker site before. I was steady enough to track it hand held and catch it between the trees. Now I'm doing my AP with a superzoom camera and will try it out for the ISS.

On my Nikon i mostly used a 105mm f2.8 macro lense. Soon before I had the stroke I started using the 70-200mm f2.8 but hadn't tried it on the ISS yet. Holds focus nicely, my sigma 150-500 lense slowly winds itself inwards and out of focus when i point it up.

As for focus I have taken focus off the shutter button on several of my cameras and reassigned to othe buttons. On the D800e I use a button for continuous focus for the iss. works very well. a quick dab on the button it locks focus fast, but hold it down its continuous focus, so i have flexibility i'm happy with. the iss is bright enough to focus the d800 quick enough, other cameras not so good.

The problem with focus is the ISS is roughly 450 miles above the ground but its distance to you will change so I wasnt sure about it being sharp enough if i stopped my lense down a bit or if i captured focus as it was rising. Plus you don't know if you got focus for certain so your whole series of shot for the night might be out of focus. So i use refocus every 15sec or so then take a burst of shots, rinses and repeat. So i end up with a ton of shots to go through and find the best focus ones. You can't really use registration and integration techniques to get a clearer shot as with other astrophotos, as in relation to you on the ground the ISS appears to rotate but you might be lucky with fast bursts to combine.